Maxillary nerve block in management of maxillary bone fractures: Our experience.

BACKGROUND AND OBJECTIVES: The objective of this study is to evaluate the intraoral high tuberocity maxillary nerve block technique in zygoma and arch fracture reduction and fixation. STUDY AND
DESIGN: This study was carried out at Arvind Multi-Specialty Hospital, Namakkal, Tamil Nadu on seven male patients with zygomatic bone and arch fracture.
MATERIALS AND METHODS: Intraoral high tuberocity maxillary nerve block administered in seven patients for management of isolated zygomatic bone and arch fracture. Lidocaine 2% measuring 4 mL with 1:80000 adrenaline anesthetic solutions was used to anesthetize maxillary nerve through a 3.2 cm length and 24G, needle. The following parameters were evaluated namely onset of anesthesia, nerve block duration, outcome of treatment and Patient's comfort.
RESULTS: The blocks were effective and patients were comfortable without pain during initial stage of surgery, but in latter stages two patients had mild to moderate pain. Duration of block varied from 60 to 90 min while onset varied from 3 to 10 min. There were vascular punctures in three patients, however, without hematoma.
CONCLUSIONS: The maxillary nerve block is a good alternative option in selective cases of zygomatic bone fracture reduction.

INTRODUCTION

Regional analgesia enjoys widespread and frequent use throughout the various disciplines of medicine. Of all medical specialists, there are indeed few who utilize local or regional analgesia as effectively, as do the dentists. The dental industry has introduced a number of new local anesthetic techniques to do surgery in maxilla and mandible. Despite the advantages of many of these newer techniques, conventional needle and syringe procedures remain the cornerstone of local anesthesia for most dental practitioners.[1] This technique, the maxillary nerve block via the pterygopalitine fissure, provides the patient with a profound block of maxillary nerve and allows the dentist, the ability to do procedures anywhere in the maxillary quadrant that has been anesthetized. Facial nerve blocks may be used in ambulatory surgery as a single technique or combined with general anesthesia or intravenous sedation. They are easy to perform and may prolong postoperative analgesia.[2] Fractures of the zygomatic arch and bone injuries are common in isolated anterior side of the face due to its prominence. Regional anesthesia present several advantages over general anesthesia, including smoother recovery, fewer side effects, residual analgesia into the postoperative period, earlier discharge from the recovery room and reduced costs.[3] The objective of this study is to assess the efficacy of the maxillary nerve block in maxillary and zygomatic bone fractures reduction and fixation.

MATERIALS AND METHODS

Over a Two-year period (January 2009 to January 2011), seven patients with fractures of the zygomatic complex and maxilla fracture treated under maxillary nerve block were reported. After approval by the Hospital Ethics Committee and with the consent of patients, the maxillary nerve block was performed in seven adult patients, ASA I-II, aged between 20 and 45 year who underwent open reduction and fixation for maxillary and zygoma fractures. Internal suspension wiring, Intermaxillary fixation, reduction of zygoma and plate fixation at lateral wall of orbit were the surgical procedures done under nerve lock.

After infiltration in mucosa, and the path of the puncture with 2% lidocaine with epinephrine 1:80,000 the block was performed with a 25G and 1–5/8 inch long needle. Patients were not under sedation and not under premedication. The patient was made to lie down in supine position in operation table below the operators elbow level. Patient was asked to open the mouth partially toward side of injection. At the posterior surface of the zygomatic process of maxilla the operator's bulbous portion of index finger was placed. The finger was pointing the exact direction the needle was to follow. The needle was inserted at the mucobuccal fold bisecting the nail and superior to the maxillary second molar with the bevel toward the bone. The needle's route is upward, backward, and inward toward the pterygopalatine fissure and fossa where nerve enters the fossa through foramen rotandum. In a normal-sized adult, the needle should be inserted approximately 1¼ in from the site if insertion. The depth will vary according to the bony structures of the patient. Aspirate before depositing a few drops of local in this area and deposit 2 to 4 mL of anesthetic solution slowly in pterygopalatine fossa near maxillary nerve. Repeated aspirations are essential before injecting the anesthetic solution.[4]

The time required for the blockade, the latency, the time of analgesia, the incidence of failure, and patient comfort was assessed. In failures, second nerve block was given to make complete anesthesia.

RESULTS

The time for completion of the maxillary nerve block anesthesia in most cases was around 5 min. The onset of anesthesia ranged from 5 to 10 min. The first clinical sign of anesthesia is the loss of sensitivity of the upper teeth and gums, upper lip, lower eyelid, bridge of the nose, nasal mucosa and nasopharyngeal and maxillary sinus. The success of anesthesia was confirmed by objective and subjective tests of anesthesia. During the initial period of surgery all patients were comfortable without pain but two patients had mild to moderate pain during the late stage of surgery. Procedure completed with infiltration of anesthetic solution at the site and path of reduction during the late stage of surgery. Duration of anesthesia was 90 to 120 min. The maxillary, zygoma reduction and fixation were done successfully as in general anesthesia. The pre and postoperative X-rays of reduction and other related pictures are shown in Figures 1–6.

Figure 1

Patient with miniplate fixation for zygoma fracture, under maxillary nerve block

Figure 6

Post op X-ray shows plate fixation and suspension wiring

Plate fixation and lateral frontal suspension wiring under maxillary nerve block

Patient with left side circumzygomatic suspension wiring under Nerve block to treat Le- fort 2 fracture

Patient with right side circum zygomatic suspension wiring under LA to treat Le fort 2 type fracture

Pre op X-ray shows fracture of lateral wall of orbits, nasal bone and maxilla

DISCUSSION

The pioneers in usage of local anesthetic in treatment of fractures may be Conway, Gavin miller, Bohler, Lerda and Quenu. All the authors reported satisfactory results following the use of local anesthesia for fractures, eighty years before itself.

Compared to general anesthesia, apart from obviating the dangers of this technique in poor risk patients, maxillary nerve block offers other advantages. First, bleeding is minimized. This effect is enhanced by use of a controlled quantity of epinephrine than is possible with certain inhalation anesthetics. Second, the absence of an oral-end tracheal tube eliminates competition for the same field between surgeon and anesthesiologist. Moreover, because the laryngeal reflexes are preserved, the airway is protected from blood, tissue fragments, and packs, both during the operation and in the early postoperative period. Third, with regional anesthesia, several of the procedures that have been discussed may be performed expeditiously and less expensively.[5]

Local anesthetic infiltration of the skin and subcutaneous tissue is usually performed on the face in aesthetic plastic surgery, reconstructive or suturing of wounds. However, the reduction of facial fractures, general anesthesia has been preferred. Unlike cutaneous surgery, the maxillary nerve block may be more deeply one, requiring precise anatomical knowledge.[6] The innervations of the zygoma are done by two terminal branches of the zygomatic nerve namely zygomatico temporal and zygomatico facial, both passing through the zygomatic foramen. These branches provide sensory innervations of skin over the cheekbone, and the subcutaneous tissue. The zygomatic nerve is one of the first maxillary nerve branches accessible in pterygoid fossa.[6] For regional anesthesia of the distal branches of the maxillary nerve (zygomatic-temporal and zygomatic-facial), it is essential to block the nerve in pterygopalatine fossa, situated a few millimeters deeper than the lateral pterygoid plate.[6] To approach the maxillary nerve, it is necessary that the needle should be inserted medially a few millimeters beyond the pterygoid plate, and proceeds to enter into the pterygoid fossa, where the anesthetic solution is deposited. It is recommended not to reach further depths greater than 0.3 cm, to prevent the needle to penetrate the floor of the orbit through the infra orbital fissure.[6] The first clinical sign of anesthesia is the loss of sensitivity of the upper teeth and gums, upper lip, lower eyelid, bridge of the nose, nasal mucosa, and nasopharyngeal and maxillary sinus. The success of anesthesia was confirmed by objective and subjective tests of anesthesia.

Review of literature; Geier K.O. in his study says, “the Zygomatic fractures reduction is feasible under maxillary nerve block when performed in pterygopalatine fossa inducing anesthesia in its two distal branches: Zygomaticotemporal and zygomaticofacial nerves”. According to this author there are few reports of zygomatic orbital floor or zygomatic arch fractures reduction or maxillary fractures under regional anesthesia. Lerda and Quenu reported satisfactory results following the use of local anesthesia for fractures, in 1907 and 1908 respectively.[6]

Conway injected cocaine between the fragments to produce anesthesia in 1885 which was reported by Gavin miller, in his article in 1932. Gavin miller, in conclusion said, “Local anesthesia is the ideal form for the treatment of fractures. Many advantages have been mentioned, while there appear to be no disadvantages, once the technique has been mastered. The methods are simple, the time consumed very brief, and the relaxation and anesthesia obtained are most satisfactory”. According to Miller, “great advantage of local anesthesia is that, as it lasts from two to three hours, there is time to x-ray the fracture after it has been treated and if the position of the fragments is not satisfactory, it is possible to manipulate them again without further anesthesia”.[7]

In 2008 Bissada, et al. concluded in their article, “Closed hook reduction under light sedation and local anesthesia is feasible and safe procedure in selected cases of zygomatic fractures”.[8]

Krishnan et al. in 2008 managed Twenty five patients with isolated zygomatic arch fractures successfully under local anesthesia and sedation using the intraoral buccal sulcus approach.[9]

Mesnil M, did a prospective and descriptive study to observe the effectiveness of bilateral maxillary nerve Blocks (BMB) using a supra zygomatic approach on pain relief and consumption of rescue analgesics following CP repair in infants. In his conclusion reported, “BMB using a supra zygomatic approach seems to improve pain relief, to decrease peri-operative consumption of opioids, and to favor early feeding resumption after CP repair in infants”.[10]

Operative procedures done in this study were Reduction of zygoma through lateral orbital approach and fixation with mini plates at fronto zygomatic suture. The other procedure done was internal suspension wiring and inter maxillary fixation.

CONCLUSION

The intraoral maxillary nerve block is an ideal alternative to general anesthesia in selective case of zygomatic bone and arch fractures.